Many commercial organizations like stores, restaurants and fitness centers issue membership cards to their customers. With the membership card, a customer can use the services or buy the products offered by the card issuing organization with a differentiated service quality or at a discount. The membership cards are often made of plastic materials with the name of the card issuing organization, card image, card number, use rules, etc., printed thereon. A membership card often has an information storage section such as a magnetic strip, an IC chip, one or two dimensional bar code(s), storing therein the information of the card issuing organization and the user. The user typically carries the membership card in his/her wallet, and in use, presents the card to the card issuing organization so as to be read by a special card reading device.
The disadvantages of the conventional membership cards lie in that, if a user enjoys membership in a plurality of commercial organizations, then he or she needs to carry and manage a plurality of membership cards. For example, a modern lady often owns dozens of membership cards, and these cards will occupy a large space. Thus, the user has to use a big wallet to contain these cards, or determine in advance which cards to take with her before going out. Apparently, this is very inconvenient for the user. In addition, it will be troublesome if the user forgets to take or loses the membership card, and it may even lead to others using the membership card assuming the user's name. On the other hand, from the perspective of the merchants, due to the low usage of the membership cards caused by the inconvenience of carriage, the merchants cannot get their expected repayment for the cost of making the membership cards.